Extended-spectrum cephalosporin (ESC) resistance remains a threat since ESC are important antimicrobials used to treat infections in humans and animals. Escherichia coli is an important source of ESC-resistance genes, such as those encoding extended-spectrum β-lactamases (ESBLs). E. coli is a common commensal of lambs. Reports that contaminated food can be a source of ESC-resistant bacteria in humans and that ESBL-producing E. coli are found in sheep in Brazil led us to survey their presence in retail lamb meat. Twenty-five samples intended for human consumption were screened for ESC-resistant E. coli, and the isolates were characterized. IncI1-bla_CTX-M-8 and IncHI2-bla_CTX-M-2 were the main plasmids responsible for ESC resistance. The plasmids harbored common ESBL genes in Enterobacteriaceae from food-producing animals in Brazil. IncI1-bla_CTX-M-14 and IncF-bla_CTX-M-55 plasmids, associated with human infections, were also detected. Few CTX-M-producing E. coli have been clustered by typing methods, and some may be genetically pathogenic. The findings indicate the presence of diverse strains of E. coli, harboring important ESBL genes, in lamb meat in Brazil. Surveillance of ESC-resistant bacteria could reduce the spread of antimicrobial resistance through the food chain.

中文翻译：

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羊肉中的潜在致病性多重耐药大肠杆菌

超广谱头孢菌素 (ESC) 耐药性仍然是一个威胁，因为 ESC 是用于治疗人类和动物感染的重要抗菌素。大肠杆菌是 ESC 抗性基因的重要来源，例如那些编码超广谱 β-内酰胺酶 (ESBL) 的基因。大肠杆菌是羔羊的常见共生菌。受污染的食物可能是人类 ESC 抗性细菌的来源，并且在巴西的绵羊中发现了产 ESBL 的大肠杆菌的报告使我们调查了它们在零售羊肉中的存在。用于人类消费的 25 个样品被筛选出具有 ESC 抗性的大肠杆菌，并对分离物进行了表征。IncI1 _- bla _CTX-M-8和 IncHI2 _- bla_CTX-M-2是负责 ESC 抗性的主要质粒。这些质粒在来自巴西食用动物的肠杆菌科中含有常见的 ESBL 基因。IncI1- BLA _CTX-M-14和IncF- BLA _CTX-M-55的质粒，与人类的感染相关的，也被检测到。很少有产 CTX-M 的大肠杆菌通过分型方法聚集在一起，有些可能具有遗传致病性。研究结果表明，在巴西的羊肉中存在不同的大肠杆菌菌株，它们带有重要的 ESBL 基因。对 ESC 耐药菌的监测可以减少抗菌素耐药性在食物链中的传播。